Systems and methods for visualizing elongated structures and detecting branches therein

ABSTRACT

Computer implemented methods are disclosed for acquiring, using a processor, digital data of a portion of an elongate object, and identifying, using a processor, a centerline connecting a plurality of points within the portion of the elongate object. The methods also may include defining a first half-plane along the centerline, traversing a predetermined angular distance in a clockwise or counter clockwise direction from the first half-plane to a second half-plane to define an angular wedge, and calculating, using a processor, a view of the angular wedge between the first half-plane and the second half-plane and generating an electronic view of the angular wedge.

RELATED APPLICATION

This application claims the benefit of priority from U.S. ProvisionalApplication No. 61/882,502, filed on Sep. 25, 2013, which is hereinincorporated by reference in its entirety.

TECHNICAL FIELD

Various embodiments of the present disclosure relate generally tomedical imaging and related methods. More specifically, particularembodiments of the present disclosure relate to systems and methods forvisualizing elongated structures.

BACKGROUND

An important topic in medical imaging is the visual representation ofelongated structures, such as tubular branching structures, such as, forexample, blood vessels, or airways in volumetric data sets. To identifythese structures and visualize all branches from a primary centerline,many types of visualization methods have been utilized. However, suchmethods are limited in their ability to display the entirety of thesestructures “at a glance.”

As an example, two popular reconstruction methods for the display ofblood vessels and other branching structures are the curved planarreformation (CPR) view and the straightened curved planar reformation(sCPR) view. The CPR and sCPR views utilize the luminal centerline tocalculate a two dimensional planar view projected along the centerline.Although a planar view displays the length of the entire vessel, theseviews may not provide sufficient information on the entirecircumferential surface of the vessel at a glance. Thus, branchingvessels that leave from the surface of the vessel may not be representedat all times in these views.

Another imaging technique used in medical imaging is a maximum intensityprojection (MIP). An MIP view may display the projection of voxels withmaximum intensity along parallel rays originating from the viewpoint tothe plane of projection. This technique may display vessels of smallcaliber, since the maximum intensity along the ray is displayed andtortuous vessels may be visible in one view. However, any brightstructures along the ray may obstruct the view, and may prevent thevessels from being visualized. Additionally, this technique may notdisplay the entire circumferential surface of the vessel at a glance.

Thus, a need exists for systems and methods, which provide sufficientinformation on the entire circumferential surface of the vessel at aglance.

The foregoing general description and the following detailed descriptionare exemplary and explanatory only and are not restrictive of thedisclosure.

SUMMARY

According to certain aspects of the present disclosure, systems andmethods are disclosed for visualizing structures. One such method mayinclude: acquiring, using a processor, digital data of a portion of anelongate object; identifying, using a processor, a centerline connectinga plurality of points within the portion of the elongate object;defining a first half-plane along the centerline; traversing apredetermined angular distance in a clockwise or counter clockwisedirection from the first half-plane to a second half-plane to define anangular wedge; calculating, using a processor, a view of the angularwedge between the first half-plane and the second half-plane; andgenerating an electronic view of the angular wedge.

In some aspects, the method may include one or more of the following:further comprising, repeating the steps of traversing and calculatingfor one or more additional angular wedges of the portion of the elongateobject; further comprising, aligning views of two opposing angularwedges next to each other; wherein the portion of the elongate object isa tubular structure, and/or, wherein generating the half-planecomprises: defining an origin direction for each of the plurality ofpoints of the centerline; calculating, using a processor, a plurality ofvectors, each originating from one of the plurality of points toward theorigin direction; and combining the plurality of vectors to generate thehalf-plane. Other aspects may include one or more of the following:wherein calculating the view in an angular direction for the angularwedge between the first half-plane and the second half-plane comprises:determining vectors along the first half-plane; determining voxels alongeach of the vectors along the first half-plane; generating maximumintensity projection (MIP) rays in an angular direction around the firsthalf-plane toward a predetermined angular distance for each of thevoxels; for each MIP ray, creating a set of voxels that intersect theray computed in a predetermined angular increment, and computing amaximum intensity of the set of voxels; and projecting the computedmaximum intensity on the first half-plane. Other aspects may include oneor more of the following: wherein each of the angular wedges is the samesize; wherein calculating the view of the angular wedge comprises:determining vectors along the first half-plane and corresponding voxelsalong each of the vectors; generating maximum intensity projection (MIP)rays in an angular direction around the first half-plane for each of thevoxels; for each MIP ray, creating a set of voxels that intersect theray computed in a predetermined angular increment, and computing theintensity of a maximum intensity voxel from the set of voxels, andprojecting the computed maximum intensity on the first half-plane. Otheraspects may include one or more of the following: wherein the elongateobject comprises tubular branching structures; wherein the steps oftraversing and calculating are repeated until a complete circumferentialview of the portion of the elongate object is completed; furthercomprising assembling views of opposing angular wedges next to eachother; wherein the digital image data is generated from computedtomography imaging; and/or wherein views of opposing angular wedges aredisplayed to resemble a straightened curved planar reformation view.

According to another aspects, disclosed is a system for visualizingstructures which may include: a data storage device storing instructionsfor visualizing structures; and a processor configured to execute theinstructions to perform a method including the steps of: acquiring,using a processor, digital data of a portion of an elongate object;identifying, using a processor, a centerline connecting a plurality ofpoints within the portion of the elongate object; defining a firsthalf-plane along the centerline; traversing a predetermined angulardistance in a clockwise or counter clockwise direction from the firsthalf-plane to a second half-plane to define an angular wedge;calculating, using a processor, a view of the angular wedge between thefirst half-plane and the second half-plane; and generating an electronicview of the angular wedge.

According to certain aspects, disclosed is a non-transitory computerreadable medium for use on at least a computer system containingcomputer-executable programming instructions for visualizing structures,the instructions may be executable by the computer system for:acquiring, using a processor, digital data of a portion of an elongateobject; identifying, using a processor, a centerline connecting aplurality of points within the portion of the elongate object; defininga first half-plane along the centerline; traversing a predeterminedangular distance in a clockwise or counter clockwise direction from thefirst half-plane to a second half-plane to define an angular wedge;calculating, using a processor, a view of the angular wedge between thefirst half-plane and the second half-plane; and generating an electronicview of the angular wedge.

Additional objects and advantages of the disclosed embodiments will beset forth in part in the description that follows, and in part will beapparent from the description, or may be learned by practice of thedisclosed embodiments. The objects and advantages of the disclosedembodiments will be realized and attained by means of the elements andcombinations particularly pointed out in the appended claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the disclosed embodiments, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate various exemplary embodiments andtogether with the description, serve to explain the principles of thedisclosed embodiments.

FIG. 1 is a block diagram of an exemplary system and network forproviding visualization of elongated structures, according to anexemplary embodiment of the present disclosure.

FIG. 2A is a tubular structure with branching structures forvisualization, according to an exemplary embodiment of the presentdisclosure.

FIG. 2B is the tubular structure of FIG. 2A with an arbitrarily defined0° half-plane along a portion of the tubular structure, according to anexemplary embodiment of the present disclosure.

FIG. 3 is a block diagram of an exemplary method for performingvisualization of a tubular structure, according to an exemplaryembodiment of the present disclosure.

FIG. 4 is a side view of a tubular structure with wedge-like shapebetween two half-planes, according to an exemplary embodiment of thepresent disclosure.

FIG. 5 is an axial cross-sectional view of the tubular structure of FIG.4 with arrows indicating a direction of maximum intensity projection(MIP) rays.

FIG. 6 is an axial cross-sectional view showing division of the tubularstructure of FIG. 4 into wedge sections, according to an exemplaryembodiment of the present disclosure.

FIG. 7 is an example of a straightened curved planar reformation (sCPR)view of a portion of a tubular structure, according to an exemplaryembodiment of the present disclosure.

FIG. 8 is a single MIP in an angular direction (aMIP) view of a tubularstructure, according to an exemplary embodiment of the presentdisclosure.

FIG. 9 is a dual aMIP view of a tubular structure, arranged to resemblean sCPR view as shown in FIG. 7, according to an exemplary embodiment ofthe present disclosure.

FIG. 10 is a view of six aMIPs of a tubular structure arranged toresemble three sCPR views, according to an exemplary embodiment of thepresent disclosure.

FIG. 11 is a simplified block diagram of an exemplary computer system inwhich embodiments of the present disclosure may be implemented.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the exemplary embodiments of thedisclosure, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

As described above, a visual representation of tubular structures ingeneral, and tubular branching structures, such as blood vessels,airways, etc., is an important tool for diagnosing the health ofpatients. Current visualization techniques provide limited views oftubular structures. The present disclosure is directed to a new approachfor providing visualization of tubular structures that may display theentire circumferential surface of a tubular structure. Morespecifically, the present disclosure is directed to using patients'imaging of a tubular structure to generate a series of maximum intensityprojection views of segments of the tubular structure and assembling theviews to provide a complete circumferential visualization of the tubularstructure. Such views may be used to generate patient-specific models offlow within the tubular structure, predict medical events (e.g. cardiac,pulmonary, respiratory), including plaque rupture and/or myocardialinfarction. The visualization methods and systems of the presentdisclosure may be used to generate a physics-based simulation of flowthrough the tubular structure (e.g. blood flow and airflow) to predictthose medical events. In addition, the present disclosure includes theuse of machine learning or rule-based methods to achieve thepredictions. Furthermore, the machine-learning and rule-based methodsmay incorporate various risk factors, including patient demographics,biomarkers, and/or coronary geometry, as well as the results ofpatient-specific biophysical simulations (e.g., hemodynamiccharacteristics). If additional diagnostic test results are available,those results can be used to train a machine-learning algorithm, forexample, in making a prediction.

Referring now to the figures, FIG. 1 depicts a block diagram of anexemplary system and network for predicting coronary plaquevulnerability from patient-specific anatomic image data. Specifically,FIG. 1 depicts a plurality of physicians 102 and third party providers104, any of whom may be connected via wired and/or wireless connectionsto an electronic network 100, such as the Internet, through one or morecomputers, servers, and/or handheld mobile devices. Physicians 102and/or third party providers 104 may create or otherwise obtain imagesof one or more patients' cardiac and/or vascular systems. The physicians102 and/or third party providers 104 may also obtain any combination ofpatient-specific information, such as age, medical history, bloodpressure, blood viscosity, etc. Physicians 102 and/or third partyproviders 104 may transmit the cardiac/vascular images and/orpatient-specific information to server systems 106 over the electronicnetwork 100 via electronic devices. The information may be transmittedin any suitable manner, for example, the information may be encrypted,encoded, compressed, or otherwise digitally modified, and the serversystems 106 may decode, decrypt, decompress, or otherwise process theinformation received. Server systems 106 may include storage devices forstoring images and data received from physicians 102 and/or third partyproviders 104. Server systems 106 may also include processing devicesfor processing images and data stored in the storage devices and maytransmit, in an electronically secure manner, the processed images (e.g.the entire circumferential surface of a vessel) for display onelectronic devices in a single display or view.

FIG. 2A is a tubular structure 200 with branching structures to bevisualized, according to an exemplary embodiment of the presentdisclosure. The tubular structure 200 may be a vessel for fluid and/orairflow and may be located in any organ of the body such as the heart orlungs. In one example, the tubular structure may be all or a portion ofa blood vessel. The tubular structure 200 may have any diameter andthickness and may have one or more curved portions. The tubularstructure 200 may include one or more branches 202 and 204 and one ormore tortuous portions 206. In addition, the tubular structure mayinclude smaller tubular branches 208 and 210. The tubular structure 200may have any size and shape and may include one or more anatomicalfeatures, such as valves, clots, plaque, and/or lesions.

FIG. 3 is a block diagram of an exemplary method 300 for providingvisualization of a tubular structure, according to an exemplaryembodiment of the present disclosure. The method 300 may be performed byserver systems 106, based on information, images, and data received fromphysicians 102 and/or third party providers 104 over an electronicnetwork 100. The method of 300 may include acquiring a digitalrepresentation of patient image data at step 302. The patient image datamay be data from one or more imaging sources such as tomography (e.g.computed tomography (CT), computed tomography angiography (CCTA),singe-photon emission computed tomography (SPECT), magnetic resonanceimaging (MRI), positron emission tomography (PET), electron tomography,ultrasound, etc. The patient image data may be of one or more portionsof a patient, such as an image of a tubular structure, such as tubularstructure 200. For example, a CCTA scan of a patient may be performed toacquire an image of the patient's vessels of interest including theascending aorta, and the left/right coronary artery trees. A digitalrepresentation of the patient image data may be stored in electronicmemory, such as on a hard drive, network drive, removable memory, etc.accessible by a computational device such as a computer, laptop, DSP,server, tablet, mobile device, etc.

A patient specific model may be derived from the patient image data inany suitable manner, for example, by generating one or more connectorsconnecting points within tubular structures at step 304. One of theconnectors may be defined as the centerline of the tubular structure. Anexample of a centerline 252 of the tubular structure 200 is shown inFIG. 2B. The centerline 252 may be one of a number of manually orautomatically electronically generated centerlines that connect pointswith the tubular structure 200 and may be electronically stored.

The connectors may be generated in any suitable manner, for example froma CCTA scan that is automatic, semi-automatic, or manual. The connectorsmay include the connected points along the tubular structure. Thecenterline may identify a tubular structure of interest, such as a bloodvessel, and may have one or more branches from the tubular structure.

An origin half-plane may be defined at step 306 for the centerline ofthe tubular structure defined in 304. The origin half-plane may begenerated by defining a zero degree direction for each point in thecenterline. A vector may then be calculated originating from thecenterline point and extending in the zero degree direction. Each vectorfrom each point in the centerline may be combined to create a half-planeat zero degrees. An example of an origin half plane 402 of a tubularstructure 400 is shown in FIG. 4. As shown in FIG. 4, the origin halfplane 402 may comprise half planes 404 and 406 defining a wedge shapedsegment (a wedge) having an angle 408.

A half-plane segment may be defined at step 308 by using the zero degreedirection (half-plane) as a starting point and defining a predeterminedangular distance from the zero degree vector. The predetermined angulardistance may be any suitable distance determined by the manufacturer ofthe system or inputted by the user. For example, the predeterminedangular distance may be 15 degrees, 30 degrees, 60 degrees, 90 degrees,etc. The direction of the predetermined angular distance from the zerodegree vector may be clockwise or counterclockwise around the centerlinepoint. For each vector defined in step 306, the predetermined angulardistance from the origin vector may be calculated. For example, for eachvector defined in step 306, a vector 60 degrees from the origin vectorin a clockwise direction around the centerline point may be calculated.Each vector along the center line may be combined to create a half-planeat the predetermined angular distance.

A MIP may be calculated at step 310. The MIP may be calculated in anangular direction between the zero degree half-plane and thepredetermined angular distance. An example of MIP rays is shown in FIG.5, which shows an axial (cross-sectional) view 500 of a tubularstructure 502 with arrows indicating the direction of MIP rays 506. Forexample:

for all 0° vectors along the centerline:

-   -   1. Cast maximum intensity projection (MIP) rays in the angular        direction around the centerline towards the 60° half-plane.    -   2. For each MIP ray:        -   a. Create a set of voxels that the ray intersects, computed            in 1° increments.        -   b. Compute the maximum intensity of the set of voxels from            the previous step.    -   3. Project the voxel with maximum intensity to the originating        voxel on the 0° vector. For example, the value of the voxel with        the maximum intensity may be assigned to the originating voxel        of the 0° vector.

The steps of computing a MIP in the angular direction (an aMIP), forexample, as described above, may be performed on a graphics-processingunit (GPU) of the computational device for improved efficiency. Thecomputation of the maximum intensity may occur sequentially as describedin the above example, or in any order. For example, the computation ofthe maximum intensity may be performed for any order of vectors andvoxels for improved efficiency. An example of a single aMIP is shown inFIG. 8, view 800.

The steps of defining a half-plane segment 308 and calculating an aMIPfor the wedge at step 310 may be repeated for each wedge having thepredetermined angular distance until a full 360 degree circumferentialMIP view is obtained at step 312. For example, if the predeterminedangular distance is 60 degrees, step 308 and 310 may be repeated foreach 60 degree wedge (six times) for a total of six aMIP views. In thisexample, the wedges 602 may be constructed for the following set ofhalf-planes 600 as shown in FIG. 6:

ii.  0°-60° iii.  60°-120° iv. 120°-180° v. 180°-240° vi. 240°-300° vii.300°-360° (0°)

In some aspects, multiple wedges 602 may be computed simultaneously forimproved efficiency. In some aspects, computation of an aMIP may beoptimized by using full planes, in order to generate in a single pass awedge and its opposite wedge (e.g. 0-60 and 180-240). In such anexample, three full planes may be assembled instead of six half-plane toresemble three sCPR views placed side-by-side.

Each of the aMIP views may be assembled at step 314. As described above,an sCPR view, such as 700 of FIG. 7, may advantageously depict an entirevessel planar cross-section. However, such an sCPR may provideinsufficient circumferential information, such as of branchingstructures. As a results, the aMIP views may be assembled on a displayfor viewing in any suitable manner to resemble three sCPR views placedside-by-side. For example:

-   -   a. For the 180°-240° aMIP, the 240°-300° aMIP, and the 300°-360°        (0°) aMIP, reflect the views across the centerline. For example,        for each 0° vector along the centerline, the values of the        voxels in the opposite direction may be re-ordered to create an        inverted view.    -   b. Align the origin of the centerlines in the same direction.    -   c. Align the centerline of the 0°-60° aMIP and the reflected        180°-240° aMIP to create an image comprising two aligned aMIP        views 900 as shown in FIG. 9, to resemble the first sCPR view        700 shown in FIG. 7.    -   d. Aligning the centerline of the 60°-120° aMIP and the        reflected 240°-300° aMIP to create an image resembling a second        sCPR view.    -   e. Aligning the centerline of the 120°-180° aMIP and the        reflected 300°-360° (0° aMIP to create an image resembling a        third sCPR view.    -   f. Aligning an edge of the combined aMIP views from step (c)        with an edge of the combined aMIP views from step (d) to create        an image of four aMIP views resembling two sCPR views.    -   g. Aligning an edge of the combined aMIP views from step (f)        which form an image resembling two sCPR views with an edge of        the third sCPR view from step (e) to create an image of six aMIP        views resembling three sCPR views 1002, 1004, and 1006, as shown        in FIG. 10, view 1000.    -   h. Three planes may be used to simultaneously calculate and        display the views for improved efficiency, for example, in the        following manner:        -   i. When calculating the 0° vector, use the opposite            direction for the 180° vector.        -   ii. Combining the above to create a line. This line, when            combined with all lines for the centerline, may define the            0° plane        -   iii. Computing the 0°-60° aMIP and the 180°-240° aMIP views            simultaneously by using the line rather than the vector for            all centerline points to obtain a set of aMIP views            identical to the one calculated in step c.

The three sets of aMIP views in steps (c)-(e) may be calculatedsimultaneously by using the method described in steps (h)(i) thru(h)(iii) for improved efficiency. Embodiments of the present disclosuremay apply the MIP technique in an angular direction and may use multipleaMIPs in combination.

Using the above-disclosed technique, the entire centerline path may bevisualized and the entire circumferential surface of a vessel may bedisplayed using a set of static views in one display.

FIG. 11 provides a functional block diagram illustration of generalpurpose computer hardware platforms. FIG. 11 illustrates a network orhost computer platform as may typically be used to implement a server,such as user server systems 106 and/or any other server executing avisualization method such as method 300. It is believed that thoseskilled in the art are familiar with the structure, programming, andgeneral operation of such computer equipment and as a result, thedrawings should be self-explanatory.

A platform for a server or the like may include a data communicationinterface for packet data communication. The platform may also include acentral processing unit (CPU) in the form of one or more processors, forexecuting program instructions. The platform typically includes aninternal communication bus program storage and data storage for variousdata files to be processed and/or communicated by the platform such asROM and RAM, although the server often receives programming and data vianetwork communications. The hardware elements, operating systems, andprogramming languages of such equipment are conventional in nature, andit is presumed that those skilled in the art are adequately familiartherewith. The server also may include input and output ports to connectwith input and output devices such as keyboards, mice, touchscreens,monitors, displays, etc. Of course, the various server functions may beimplemented in a distributed fashion on a number of similar platforms,to distribute the processing load. Alternatively, the servers may beimplemented by appropriate programming of one computer hardwareplatform.

Program aspects of the technology may be thought of as “products” or“articles of manufacture” typically in the form of executable codeand/or associated data that is carried on or embodied in a type ofmachine-readable medium. “Storage” type media include any or all of thetangible memory of the computers, processors or the like, or associatedmodules thereof, such as various semiconductor memories, tape drives,disk drives and the like, which may provide non-transitory storage atany time for the software programming. All or portions of the softwaremay at times be communicated through the Internet or various othertelecommunication networks. Such communications, for example, may enableloading of the software from one computer or processor into another, forexample, from a management server or host computer of the mobilecommunication network into the computer platform of a server and/or froma server to the mobile device. Thus, another type of media that may bearthe software elements includes optical, electrical and electromagneticwaves, such as used across physical interfaces between local devices,through wired and optical landline networks and over various air-links.The physical elements that carry such waves, such as wired or wirelesslinks, optical links, or the like, also may be considered as mediabearing the software. As used herein, unless restricted tonon-transitory, tangible “storage” media, terms such as computer ormachine “readable medium” refer to any medium that participates inproviding instructions to a processor for execution.

The many features and advantages of the disclosure are apparent from thedetailed specification, and thus, it is intended by the appended claimsto cover all such features and advantages of the disclosure which fallwithin the true spirit and scope of the disclosure. Further, sincenumerous modifications and variations will readily occur to thoseskilled in the art, it is not desired to limit the disclosure to theexact construction and operation illustrated and described, andaccordingly, all suitable modifications and equivalents may be resortedto, falling within the scope of the disclosure.

Other embodiments of the disclosure will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritof the invention being indicated by the following claims.

What is claimed:
 1. A computer-implemented method for visualizingelongate objects, the method comprising: acquiring, using a processor,digital data of a portion of an elongate object; identifying, using aprocessor, a centerline connecting a plurality of points within theportion of the elongate object; defining a first half-plane along thecenterline; traversing a predetermined angular distance in a clockwiseor counter clockwise direction from the first half-plane to a secondhalf-plane to define an angular wedge; calculating, using a processor, aview of the angular wedge between the first half-plane and the secondhalf-plane; and generating an electronic view of the angular wedge. 2.The method of claim 1, further comprising, repeating the steps oftraversing and calculating for one or more additional angular wedges ofthe portion of the elongate object.
 3. The method of claim 2, furthercomprising, aligning views of two opposing angular wedges next to eachother.
 4. The method of claim 1, wherein generating the half-planecomprises: defining an origin direction for each of the plurality ofpoints of the centerline; calculating, using a processor, a plurality ofvectors, each originating from one of the plurality of points toward theorigin direction; and combining the plurality of vectors to generate thehalf-plane.
 5. The method of claim 1, wherein calculating the view ofthe angular wedge between the first half-plane and the second half-planecomprises: determining vectors along the first half-plane; determiningvoxels along each of the vectors along the first half-plane; generatingmaximum intensity projection (MIP) rays in an angular direction aroundthe first half-plane toward a predetermined angular distance for each ofthe voxels; for each MIP ray, creating a set of voxels that intersectthe ray computed in a predetermined angular increment, and computing amaximum intensity of the set of voxels; and projecting the computedmaximum intensity on the first half-plane.
 6. The method of claim 1,wherein calculating the view of the angular wedge comprises: determiningvectors along the first half-plane and corresponding voxels along eachof the vectors; generating maximum intensity projection (MIP) rays in anangular direction around the first half-plane for each of the voxels;for each MIP ray, creating a set of voxels that intersect the raycomputed in a predetermined angular increment, and computing theintensity of a maximum intensity voxel from the set of voxels, andprojecting the computed maximum intensity on the first half-plane. 7.The method of claim 1, wherein the elongate object comprises tubularbranching structures.
 8. The method of claim 1, wherein the steps oftraversing and calculating are repeated for a plurality of angularwedges until a complete circumferential view of the portion of theelongate object is completed.
 9. The method of claim 8, furthercomprising assembling views of opposing angular wedges next to eachother.
 10. The method of claim 9, wherein the views of the opposingangular wedges are displayed to resemble a straightened curved planarreformation view.
 11. The method of claim 1, wherein the digital imagedata is generated from computed tomography imaging.
 12. A system forvisualizing structures comprising, the system comprising: a data storagedevice storing instructions for visualizing structures; and a processorconfigured to execute the instructions to perform a method including thesteps of: acquiring, using a processor, digital data of a portion of anelongate object; identifying, using a processor, a centerline connectinga plurality of points within the portion of the elongate object;defining a first half-plane along the centerline; traversing apredetermined angular distance in a clockwise or counter clockwisedirection from the first half-plane to a second half-plane to define anangular wedge; calculating, using a processor, a view of the angularwedge between the first half-plane and the second half-plane; andgenerating an electronic view of the angular wedge.
 13. The system ofclaim 12, further comprising, repeating the steps of traversing andcalculating for one or more additional angular wedges of the portion ofthe elongate object.
 14. The system of claim 13, further comprising,aligning views of two opposing angular wedges next to each other. 15.The system of claim 12, wherein generating the one or more centerlinescomprises: defining an origin direction for each of the plurality ofpoints of the centerline; calculating, using a processor, a plurality ofvectors, each originating from one of the plurality of points toward theorigin direction; and combining the plurality of vectors to generate thehalf-plane.
 16. The system of claim 12, wherein calculating the view ofthe angular wedge between the first half-plane and the second half-planecomprises: determining vectors along the first half-plane; determiningvoxels along each of the vectors along the first half-plane; generatingmaximum intensity projection (MIP) rays in an angular direction aroundthe first half-plane toward a predetermined angular distance for each ofthe voxels; for each MIP ray, creating a set of voxels that intersectthe ray computed in a predetermined angular increment, and computing amaximum intensity of the set of voxels; and projecting the computedmaximum intensity on the first half-plane.
 17. The system of claim 12,wherein calculating the view of the angular wedge comprises: determiningvectors along the first half-plane and corresponding voxels along eachof the vectors; generating maximum intensity projection (MIP) rays in anangular direction around the first half-plane for each of the voxels;for each MIP ray, creating a set of voxels that intersect the raycomputed in a predetermined angular increment, and computing theintensity of a maximum intensity voxel from the set of voxels, andprojecting the computed maximum intensity on the first half-plane. 18.The system of claim 12, wherein the calculating step is performed by agraphics processing unit.
 19. The system of claim 12, wherein theelongate object comprises tubular branching structures.
 20. Anon-transitory computer readable medium for use on at least a computersystem containing computer-executable programming instructions forvisualizing structures, the instructions being executable by thecomputer system for: acquiring, using a processor, digital data of aportion of an elongate object; identifying, using a processor, acenterline connecting a plurality of points within the portion of theelongate object; defining a first half-plane along the centerline;traversing a predetermined angular distance in a clockwise or counterclockwise direction from the first half-plane to a second half-plane todefine an angular wedge; calculating, using a processor, a view of theangular wedge between the first half-plane and the second half-plane;and generating an electronic view of the angular wedge.